JPH06115260A - Thermal transfer image receiving sheet - Google Patents

Abstract

PURPOSE:To make an adhesive performance and a cushion performance excellent by forming a middle layer of a chlorinated polypropylene resin. CONSTITUTION:There are arranged a base material sheet and a dye receiving layer formed on its surface through a middle layer, which is formed by a chlorinated polypropylene resin. The middle layer includes a white pigment filling agent and/or a fluorescent whiteness increasing agent. Besides, the base material sheet is composed of pipe paper, synthetic paper or synthetic resin film. Various kinds of plastic films or sheets and the like may be usable, and further, a white and non-transparent film which is formed with addition of the white pigment, the filler or a foamed foam sheet and the like may be usable and there is no special limitation. About 10-50mum is preferable as a thickness of these base sheets. As the chlorinated polypropylene resin on a surface of the base material sheet, either a low chlorinated material or a high chlorinated material may be usable, but especially a low chlorinated polypropylene including chlorine content of 20-40 weight %, is preferable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermal transfer image-receiving sheet, and more specifically, it provides a thermal transfer image-receiving sheet which is excellent in the adhesiveness of a dye receiving layer and in the cushioning property at the time of printing and capable of forming a high density and high resolution image. To aim.

[0002]

2. Description of the Related Art Conventionally, various thermal transfer methods are known. Among them, a sublimable dye is used as a recording agent, and this is carried on a base material sheet such as paper or a plastic sheet to form a thermal transfer sheet. There has been proposed a method of forming various full-color images on a thermal transfer image-receiving sheet that can be dyed with a dye, for example, a thermal transfer image-receiving sheet having a dye-receiving layer on the surface of paper or a plastic film.

In this case, a thermal head of a printer is used as a heating means, and a large number of three-color or four-color dots are transferred to a thermal transfer image-receiving sheet by heating for an extremely short time, and the original is formed by the multi-color dots. It reproduces a full-color image. The image formed in this way is
It is very vivid because the coloring material used is a dye,
And because it is excellent in transparency, the obtained image has excellent reproducibility and gradation of intermediate colors, is similar to the image by conventional offset printing or gravure printing, and has a high quality image comparable to a full color photographic image. It can be formed.

[0004]

The thermal transfer image-receiving sheet used in the sublimation type thermal transfer system as described above includes:
Pulp paper, plastic sheet, laminated sheet of plastic sheet and paper, synthetic paper, etc. as the base sheet, and the surface of the resin is made of thermoplastic resin such as polyester resin, vinyl chloride resin, vinyl chloride / vinyl acetate copolymer resin, etc. However, in these image-receiving sheets, there is a problem that the dye-receiving layer may be peeled off by the heat of the thermal head during thermal transfer, or may be easily peeled off with an adhesive tape or the like. Further, sufficient whiteness is required to form a clear image, but if a large amount of white pigment is included in the dye receiving layer, the dyeing property of the dye is deteriorated. Further, in order to eliminate defects such as print defects and white spots and obtain a high-resolution image, the image-receiving sheet is required to have sufficient cushioning property in order to improve the contact between the thermal head and the dye-receiving layer. Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a thermal transfer image-receiving sheet excellent in adhesiveness, whiteness, cushioning property and the like.

[0005]

The above object can be achieved by the present invention described below. That is, the present invention is a thermal transfer image-receiving sheet comprising a substrate sheet and a dye receiving layer formed on the surface of the substrate via an intermediate layer, the intermediate layer comprising a chlorinated polypropylene resin.

[0006]

By forming the intermediate layer from a chlorinated polypropylene resin, it is possible to provide a thermal transfer image-receiving sheet excellent in adhesiveness and cushioning. Further, by adding a white pigment, a filler, a fluorescent brightening agent, etc. to the intermediate layer, the background color of the base material is hidden without impairing the dye-dyeability of the dye-receiving layer, and the dye-receiving layer with high whiteness is obtained. Is formed.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described in more detail with reference to preferred embodiments. Examples of the base sheet used in the present invention include synthetic paper (polyolefin-based, polystyrene-based, etc.), high-quality paper, art paper, coated paper, cast-coated paper, wallpaper, backing paper, synthetic resin or emulsion-impregnated paper, synthetic rubber latex. Films or sheets of various plastics such as impregnated paper, synthetic resin internal paper, paperboard, cellulose fiber paper, polyolefin, polyvinyl chloride, polyethylene terephthalate, polystyrene, polymethacrylate, polycarbonate, etc. can be used, and their synthesis is also possible. A white opaque film formed by adding a white pigment or a filler to a resin or a foamed foamed sheet can be used, and there is no particular limitation. The thickness of these substrate sheets is about 10
It is preferably about 500 μm.

The above chlorinated polypropylene resin for forming the intermediate layer on the surface of the base sheet may be either a low chlorinated compound or a high chlorinated compound, but especially the chlorine content is 20 to 4
0 wt% low chlorinated polypropylene is preferred. Further, the chlorinated polypropylene may be subjected to various modifications such as maleic acid modification, alcohol modification and epoxy modification. Further, the intermediate layer in the present invention may be a mixture of chlorinated polypropylene and other resin such as acrylic resin, urethane resin, polyester resin, vinyl chloride resin, vinyl acetate resin and ethylene / vinyl acetate copolymer. . In that case, the total chlorinated polypropylene is 10
It is desirable that it be present in a weight percentage or more. The intermediate layer may be formed by various methods such as a gravure coating method, a screen printing method and a cast coating method, but is not limited to these methods.

In a preferred embodiment of the present invention, the above intermediate layer contains a white pigment, a filler and / or an optical brightener. As a method of incorporating these white pigments and the like, the white pigment and the like may be incorporated in the coating liquid used when forming the intermediate layer. The white pigment or the filler has the purpose of improving the whiteness and hiding power of the intermediate layer and preventing the background color of the base sheet from adversely affecting the image. Examples of such white pigments or fillers include white pigments such as titanium oxide, zinc oxide, kaolin clay, calcium carbonate and fine powder silica. The amount of the white pigment or the like added varies depending on the type of the pigment or the like used, but is generally about 1 to 500 parts by weight per 100 parts by weight of the intermediate layer forming resin.

Further, the fluorescent whitening agent eliminates the yellowing of the resin of the intermediate layer and improves the whiteness, and for example, stilbene type, diaminodiphenyl type, oxazole type, imidazole type, thiazole type, coumarin. Well-known optical brighteners such as those of the system, naphthalimide type and thiophene type are used. These fluorescent whitening agents are dissolved in the resin for the intermediate layer and have a sufficient effect at an extremely low concentration, for example, 0.01 to 5% by weight.

The dye receiving layer formed on the surface of the substrate sheet is for receiving the sublimable dye transferred from the thermal transfer sheet and maintaining the formed image. As the binder resin for forming the dye receiving layer, for example,
Polyolefin resin such as polypropylene, vinyl halide resin such as polyvinyl chloride and polyvinylidene chloride, vinyl resin such as polyvinyl acetate and polyacrylic ester, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polystyrene resin , Polyamide resins, copolymer resins of olefins such as ethylene and propylene with other vinyl monomers, ionomers, cellulosic resins such as cellulose diacetate, polycarbonates, and the like. Particularly preferred are vinyl resins and polyesters. It is a resin.

The dye receiving layer in the thermal transfer image-receiving sheet of the present invention requires the binder resin as described above, such as a releasing agent, an antioxidant, an ultraviolet absorber, etc., on at least one surface of the base sheet. Addition of various additives, dissolved in a suitable organic solvent or dispersed in an organic solvent or water, for example, gravure printing method, screen printing method, reverse roll coating method using a gravure plate, etc. It is formed by applying and drying by a forming means.

The dye receiving layer preferably contains a releasing agent in order to impart a good releasing property to the thermal transfer sheet. Preferred releasing agents include silicone oils, phosphate ester type surfactants, fluorine type surfactants and the like, but silicone oils are preferable. Examples of the silicone oil include epoxy-modified, alkyl-modified, amino-modified, carboxyl-modified, alcohol-modified, fluorine-modified,
Modified silicone oils such as alkyl aralkyl polyether modified, epoxy / polyether modified, and polyether modified are desirable. As the release agent, one type or two or more types are used. The amount of the release agent added is preferably 1 to 20 parts by weight with respect to 100 parts by weight of the binder resin. If the addition amount range is not satisfied, problems such as fusion of the thermal transfer sheet and the dye receiving layer or reduction of printing sensitivity may occur. The dye receiving layer formed as described above may have any thickness, but it is generally 1 to 50 μm thick. Further, such a dye receiving layer is preferably a continuous coating, but it may be formed as a discontinuous coating by using a resin emulsion or a resin dispersion.

In the present invention, the dye receiving layer is preferably formed by a transfer method. That is, when a pulp paper base material is used as the sheet, surface smoothness may be insufficient, and in this case, unevenness or pinholes may occur in the dye receiving layer formed by the above coating method. However, according to the transfer method, such a problem does not occur. The transfer method is, for example, to form the dye receiving layer on the surface of a film having good releasing property such as polyester film, and further to form an adhesive layer made of a resin having a glass transition temperature of −80 to 20 ° C. on the surface. This is a method in which the pressure-sensitive adhesive layer is formed so as to face the surface of the pulp paper base material and is bonded with a laminator or the like, and then the polyester film is peeled off.

For the purpose of improving the transportability of the image-receiving sheet in the printer, a resin having excellent lubricity such as an acrylic resin or an acrylic silicone resin, or a suitable sliding agent for the same is provided on the opposite surface of the dye receiving layer. It is also preferable to add a hydrophilic particle to form a slip layer having a thickness of, for example, about 1 to 5 g / m ² . The thermal transfer sheet used when performing thermal transfer using the thermal transfer image-receiving sheet of the present invention as described above,
A dye layer containing a sublimable dye is provided on paper or polyester film, and any conventionally known thermal transfer sheet can be used as it is in the present invention. As a means for applying heat energy during thermal transfer, any conventionally known applying means can be used, and for example, the recording time is controlled by a recording device such as a thermal printer (for example, video printer VY-100 manufactured by Hitachi, Ltd.). By doing so, the intended purpose can be sufficiently achieved by applying thermal energy of about 5 to 100 mJ / mm ² .

[0016]

EXAMPLES Next, the present invention will be described more specifically with reference to Examples and Comparative Examples. In the text, parts and% are based on weight unless otherwise specified. Example 1 200 μm-thick synthetic paper (trade name: YUPO, manufactured by Oji Yuka)
The coating solution for the intermediate layer having the following composition was applied to the surface of the above with a bar coater at a rate of 1.0 g / m ² when dried, dried with a dryer and then dried in an oven at 100 ° C for 5 minutes to form the intermediate layer. The coating solution for a receiving layer described below is formed on the intermediate layer by a bar coater at a rate of 3.0 g / m ² when dried, and dried in an oven at 100 ° C for 5 minutes to obtain the thermal transfer image-receiving of the present invention. Got the sheet. Composition of coating liquid for intermediate layer : Chlorinated polypropylene (Hardlen 13B, manufactured by Toyo Kasei) 50 parts Ethylene / vinyl acetate copolymer (Evaflex 40Y, manufactured by Mitsui DuPont Chemical) 50 parts Optical brightener (Ubitex OB, Ciba Geigy) 0.1 part Toluene 100 parts Receptor layer coating liquid composition ; Polyester resin (Vylon 103, Toyobo) 100 parts Amino-modified silicone (X-22-343, Shin-Etsu Chemical Co., Ltd.) 3 parts Epoxy-modified silicone (KF) -393, manufactured by Shin-Etsu Chemical Co., Ltd.) 3 parts Methyl ethyl ketone / toluene (weight ratio (1/1)) 500 parts

Example 2 An expanded polypropylene sheet (TOYOPEARL SS # 35, manufactured by Toyobo Co., Ltd., thickness: 35 μm) was coated with the following coating solution for the intermediate layer at a solid content of 2 g / m ² and dried, and then its surface A coating solution for the receiving layer having the following composition was applied to the above with a bar coater at a rate of 2.0 g / m ² when dried, tentatively dried with a dryer, and then dried in an oven at 100 ° C. for 30 minutes to obtain the dye receiving layer. To obtain a thermal transfer image-receiving sheet of the present invention. Coating composition for intermediate layer ; Chlorinated polypropylene (Hardlen 15LPB, manufactured by Toyo Kasei) 100 parts Titanium oxide (TCR-10, manufactured by Tochem Products) 100 parts Toluene 100 parts Coating solution composition for receiving layer ; Vinyl chloride / acetic acid Vinyl copolymer resin (VYHD, manufactured by Union Carbide) 100 parts Epoxy-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 3 parts Amino-modified silicone (KP343, Shin-Etsu Chemical Co., Ltd.) 3 parts Methyl ethyl ketone / toluene (weight ratio (1 / 1)) 400 copies

Example 3 The surface of a 100 μm thick polyester film (trade name “Lumirror”, manufactured by Toray Industries, Inc.) was coated with an intermediate layer coating solution having the following composition by a bar coater to give 3.0 g / m ² when dried. The coating solution for the receiving layer is applied at a ratio of 4.0 g / dry on the intermediate layer.
A thermal transfer receiving sheet of the present invention was obtained by coating with a bar coater at a ratio of m ² and drying. Coating solution composition for intermediate layer : Chlorinated polypropylene (Hardlen 15LPB, manufactured by Toyo Kasei) 50 parts Titanium oxide (TCA888, manufactured by Tochem Products) 100 parts Toluene 100 parts Coating solution composition for receiving layer ; vinyl chloride / vinyl acetate Polymerized resin (VYHD, Union Carbide Co.) 100 parts Amino-modified silicone (X-22-343, Shin-Etsu Chemical Co., Ltd.) 2 parts Epoxy-modified silicone (KF-393, Shin-Etsu Chemical Co., Ltd.) 2 parts Methyl ethyl ketone / toluene (weight ratio) (1/1)) 100 copies

Comparative Example 1 A thermal transfer image-receiving sheet of Comparative Example was obtained in the same manner as in Example 1 except that the following thermoplastic resin solution was used as the coating liquid for the intermediate layer. Composition of coating liquid for intermediate layer : Acrylic resin (Dianal BR85, manufactured by Mitsubishi Rayon) 20 parts Toluene 100 parts Comparative Example 2 Thermal transfer image reception of Comparative Example in the same manner as in Example 1 except that the intermediate layer is not formed in Example 2. Got the sheet.

On the other hand, a dye layer ink having the following composition was prepared and heat-treated on the back surface thereof to a polyethylene terephthalate film having a thickness of 6 μm and a dry coating amount of 1.0 g / m ²
Coated with a wire bar and dried, and then a few drops of silicone oil (X-41.4003A, made by Shin-Etsu Silicone) is dropped on the back surface with a dropper, then spread over the entire surface and subjected to back surface treatment coating to obtain a thermal transfer film. It was Ink composition for dye layer : Disperse dye (Kayaset Blue 714, manufactured by Nippon Kayaku) 4.0 parts Ethyl hydroxycellulose (manufactured by Hercules) 5.0 parts Methyl ethyl ketone / toluene (weight ratio 1/1) 80.0 parts Dioxane 10.0 parts The thermal transfer film is superposed on the surface of the receiving layer of each of the image receiving sheets, and the output is 1 W / dot using a thermal head.
Pulse width 0.3 to 0.45 msec. When a cyan image was formed by printing under the condition of a dot density of 3 dots / mm, when the thermal transfer image receiving sheet of the example was used,
Although there was no problem of peeling of the dye receiving layer and there was no defect such as color loss, the dye receiving layer was partially peeled off when the thermal transfer image receiving sheet of Comparative Example was used. In addition, the image was inferior in quality because defective parts such as color loss and the like were observed.

[0022]

[Effect] According to the present invention as described above, by forming the intermediate layer from a chlorinated polypropylene resin, it is possible to provide a thermal transfer image-receiving sheet excellent in cushioning property. or,
By adding a white pigment, a filler, a fluorescent brightening agent and the like to the intermediate layer, the background color of the base material is hidden and a dye receiving layer having high whiteness is formed.

Claims (3)

[Claims] 1. A thermal transfer image-receiving sheet comprising a base sheet and a dye receiving layer formed on the surface of the base sheet via an intermediate layer, wherein the intermediate layer is made of a chlorinated polypropylene resin. 2. The thermal transfer image-receiving sheet according to claim 1, wherein the intermediate layer contains a white pigment, a filler and / or a fluorescent whitening agent. 3. The thermal transfer image-receiving sheet according to claim 1, wherein the base sheet is made of pulp paper, synthetic paper or synthetic resin film.